Or, what makes a member stop using your club and leave for another club a few miles away?

These kinds of retention questions that keep some club operators awake at night are nothing new in the fitness industry. This topic has been part of Club Industry's coverage for years – we have nearly 1,000 articles from our staff, experts in the industry and leading sponsors that can help you dig into retention strategy from several angles.

Add this blog entry to the ever-growing list.

Two big names in the fitness industry recently revealed user behavior trends that may help you develop a better retention strategy for your club. The details come separately to Club Industry from fitness class subscription service ClassPass, New York City, and cloud-based business management software platform Mindbody, San Louis Obispo, California. The findings examine American activity trends across each of their platforms.

ClassPass' findings come from a recently released 20-page white paper that examined utilization trends among its 8,500 partner studios and gyms in 2015. ClassPass defined utilization as the percent of a studio's available inventory on ClassPass that is booked. An increase in utilization occurs when more available ClassPass spots are booked, and lower utilization occurs when there are fewer reservations in relation to total spots available.

The study found that beyond major differentiating factors, such as location and type of workout, ClassPass users were looking at these three factors: class length, availability of showers and availability of lockers or safe storage. ClassPass found its partners who offer 45-minute to 55-minute classes, showers and lockers saw higher utilization rates.

ClassPass found that a shorter group exercise class positively affected utilization at its partner gyms and studios. (Photo by Thinkstock.)

ClassPass determined that classes 45 minutes to 55 minutes in length have between an 11 percent and 23 percent higher utilization than the average class on ClassPass. The company compared 45-minute, 50-minute and 55-minute classes against class lengths of 60 minutes to 90 minutes in 5-minute increments, respectively. In the Los Angeles market, a 45-minute to 55-minute class saw higher utilization with a range between 20 percent and 63 percent.

The ClassPass findings were derived from analysis of user reservations whose monthly cycles began on Jan. 1, 2015, and ended on Nov. 30, 2015. ClassPass stressed that its findings are a reflection of utilization driven only through its platform, and operators of studios and gyms should consider their own market before making any programming or facility changes.

Bright Architecture, exhale and Uplift contributed to the ClassPass report. Annbeth Eschbach, exhale CEO and founder, will receive Club Industry's Lifetime Achievement Award at the Club Industry Show in Chicago in October.

Here are the highlights from Mindbody, which analyzed data dating back to 2005. The data show an increase in late night usage:

Late night workout: There were 220,069 visits to fitness studios between 9 p.m. and midnight in 2015, which is a 48-fold increase from 2005 (when there were 4,566 visits between 9 p.m. and midnight).

Namaste in class: Out of all fitness studio visits in the United States in January 2016 from 8 p.m. to 3 a.m., 41 percent of visits were to yoga studios, 28 percent of visits were to general fitness studios and 8 percent were to dance studios.